The global measles outbreak has reached a cruise ship anchored off St. Lucia island in the Caribbean.

Health officials there have ordered the ship, believed to be owned by the Church of Scientology, to remain in port after it learned a passenger had the measles virus, CNN reported.

“Chief Medical Officer Dr. Merlene Fredericks-James said that after internal discussions and talks with the Pan American Health Organization, “we thought it prudent that we quarantine the ship,’” CNN reported.

Fredericks-James said that the highly contagious disease could be rapidly spread through a population in such a setting.

According to a schedule on the St. Lucia Air and Sea Ports Authority website, the ship arrived on Tuesday and was going to leave the port on Thursday before the quarantine was put in place, CNN reported.

CNN reported that the Church of Scientology did not respond to inquiries but its website describes the ship as a “religious retreat.”

The boat can accommodate 450 people, but no information about how many passengers were on the boat was included in the CNN report.

“Quarantine is a word that people respond to very strongly, but it’s actually one of the strongest tools in the public health tool kit,” Rebecca Katz, director of the Center for Global Health Science and Security at Georgetown University, told CNN. “But because it curtails civil liberties, most public health officials are very wary to utilize it.”

“Sometimes people feel like they’re being treated like a criminal,” Katz said. “The point is to be treated like you’re doing something that is contributing to your society and only be treated like a criminal if you disobey.”

“Fredericks-James said health officials were using authority given to them by the nation’s quarantine act and public health act,” CNN reported.

The Centers for Disease Control and Prevention (CDC) on Monday said that there are 704 confirmed cases of measles in 22 states in the United States, but measles outbreaks have also been reported around the globe.

Health officials said this recent outbreak is the largest since measles was officially declared eliminated in the United States in 2000.